I used to pass (color) parameters to \startuseMPgraphic with:
\startuseMPgraphic{square}{acolor}draw unitsquare withcolor \MPvar{acolor}; % or \MPcolor{acolor}
In both cases I get the following error:
metapost > initializing instance 'metafun' using format 'metafun'metapost > loading 'metafun' as '/Users/hansm/TeX/context-09/tex/texmf-context/metapost/context/base/metafun.mpiv' using method 'default'metapost > initializing number mode 'scaled'check > missing or ungrouped '=' after 'green' in line '7 (442>square:)'
Has something changed in this mechanism of parameter use, or am I doing something wrong?